Please refer to FIG. 1A and FIG. 1B. FIG. 1A shows a conventional probing system. FIG. 1B shows a probing device shown in FIG. 1A. The probing system 1000 includes a test head 1100, a conventional probing device 1200, and a prober 1400. The probing device 1200 includes a probe interface board 1210, a pogo tower 1220, and a probe card 1230. The probing device 1200 is mounted on the test head 1100. The test signals sent from the test head 1100 are passed through the probe interface board 1210, the pogo tower 1220, and the probe card 1230 in turn, and then transmitted into a device under test (DUT) 1300 via a plurality of vertical probes 1231 of the probe card 1230. Because the signal transmission path is of a relatively long distance, signal failure is possible to occur when a plurality of high-frequency test signals are transmitted.
To try to overcome the above described problems, person skilled in the art had provided another probing system and device. Please refer to FIG. 2 which shows another conventional probing system. A conventional probing device 10 includes a probe interface board 12, a space transforming plate 14, and a vertical probe assembly 19. The probe interface board 12 is electrically connected with the space transforming plate 14 via a plurality of solders. The vertical probe assembly 19 includes a guide plate 192 and a plurality of vertical probes 194. The guide plate 192 is mounted on the bottom surface of the space transforming plate 14. The vertical probes 194 are penetrated through the guide plate 192 and electrically connected with the space transforming plate 14.
The probing device 10 is a direct-docking probing device. No probe card is disposed in the probing device 10, so that the signal transmission path is shorter and the probing device 10 is suitable for carrying the high-frequency signals. In the probing device 10 (of direct-docking type), the probe interface board 12 is used to replace the circuit board of the probe card. Because the area of the probe interface board 12 is several times larger than that of the circuit board of the probe card, more electronic components can be mounted on the probe interface board 12. Therefore, the probe interface board 12 has improved test effectiveness and can detect more types of DUTs. In addition, due to having a larger area, the probe interface board 12 can be configured to test a larger number of DUTs at the same time.
Whether referring to the probing device 10 in FIG. 2 or the probing device 1200 in FIG. 1B, both probing devices 10, 1200, each of which requires to use a seating surface for a flatness standard. The flatness is defined as the difference between the maximum and minimum distances from the tip of the probe to the seating surface.
However, the probe interface board 12 and the space transforming plate 14 are connected together by reflowing. During the reflowing operation, the probe interface board 12 must sustain high temperature heating, so that the probe interface board 12 is possible to become damaged. In addition, the unit cost of the probe interface board 12 is higher due to having more electronic components disposed thereon, and the cost burden on the user is thereby increased.
In order to try to solve the above described problems, another conventional probing device 20 shown in FIG. 3 is provided. The probing device 20 includes a probe interface board 22, a space transforming plate 24, a fixing frame 25, a supporting plate 26, a plurality of electrical contacts 28, and a vertical probe assembly 29. The supporting plate 26 is disposed between the probe interface board 22 and the space transforming plate 24. The electrical contacts 28 are disposed in the supporting plate 26. The fixing frame 25 is mounted on the probe interface board 22. The holding portion 251 of the fixing frame 25 is holding on the space transforming plate 24, in order to ensure adequate electrical conductivity between the electrical contacts 28 and the space transforming plate 24. The electrical contacts 28 and the probe interface board 22 are connected without the reflowing operation, so that the probe interface board 22 does not require sustaining higher temperature heating, and thus the probe interface board 22 has longer service life.
In today's industry, the space transforming plate 24 is made by the back-end-of-line (BEOL) semiconductor manufacturing process, i.e. packaging process, so that the thickness of the space transforming plate 24 has become thinner. However, the height from the bottom surface of the probe interface board 22 to the tip of the vertical probe assembly 29 is limited by the usage environment; thus, such height is harder to be adjusted when the space transforming plate 24 becomes thinner. Taiwan patent publication number 201003078 discloses a thickening plate. The thickening plate, disposed between the electrical contacts and the space transforming plate, can solve the problems caused by the thinner space transforming plate. However, the thickening plate is mainly used in the vertical probe card instead of the direct-docking probing system.
Furthermore, the area of the space transforming plate 24 becomes larger due to the corresponding larger area of the probe interface board 22. Because of the thinner thickness and the larger area of the space transforming plate 24, the space transforming plate 24 will have larger deformation when the electrical contacts 28 apply an elastic force on it. Therefore, the probes of the vertical probe assembly 29 cannot accurately be contacted with the device under test. In addition, when the vertical probe assembly 29 is contacted with the device under test, the device under test will apply a reaction force back to the vertical probe assembly 29, so as to deflect the space transforming plate 24 toward the probe interface board 22, thus compressing and damaging the electrical contacts 28.
Hence, there is a need in the art for preventing the space transforming plate from being deflected in the direct-docking probing device.